Inflatable cell for anti-eschar mattresses

ABSTRACT

The invention relates to an inflatable cell for anti-eschar mattresses, including an inflatable housing having an elongate shape and two main opposed side surfaces, as well as several oblong welds that have a main longitudinal axis substantially perpendicular to the main longitudinal axis of the housing, which are spaced apart along the length of the housing, and which connect two main opposed side surfaces of the housing together.

TECHNICAL FIELD

The present invention relates to the field of inflatable anti-escharmattresses used in hospitals or similar settings or in individual homes,for people confined to bed rest for long periods of time. The object ofthe invention is a new inflatable cell for anti-eschar mattresses, aswell as an anti-eschar mattress including a plurality of inflatablecells.

BACKGROUND OF THE INVENTION

When a person is bedridden for a long time on a traditional mattress,the parts of the person's body that are in prolonged contact with themattress undergo compressions, which ultimately cause eschars to form.

With the aim of offsetting this problem of eschar formation, onesolution known to date consists of proposing anti-eschar inflatablemattresses, which include a plurality of juxtaposed inflatable cells.This type of mattress is for example described in U.S. Pat. No.5,704,084.

The cells of an anti-eschar mattress can be inflated individually usinga compressor or equivalent means and according to a so-called “dynamic”mode characterized by an inflation sequence and cycle that arepredefined, so as to reduce the compression time of the body parts incontact with the cells of the mattress. For example, the inflation ofevery other cell is done cyclically. The characteristics of this dynamicmode are generally configurable so as to best adapt them to thebedridden person.

In this type of anti-eschar mattress inflatable cell, for the comfort ofthe bedridden person and for effective draining of the eschars, it isimportant to optimize the support surface of the cell designed to be incontact with the bedridden person. In particular, if the width of thesupport surface of each cell of a mattress is too large, in dynamic modethere is a risk of tourniquet effect on the bedridden person.Conversely, if the width of the support surface of each cell is toosmall, the dynamic relief effect is no longer felt by the bedriddenperson.

Another problem encountered during confinement to bed of a person in ahospital or similar setting is related to accidental falls by thebedridden person. This problem is magnified and becomes critical whenthe bedridden people have reduced motor abilities, such as for examplepeople having undergone surgery, people who are completely or partiallyparalyzed, or the elderly.

With the aim of reducing these risks of accidental falls, in Frenchpatent application FR 2 883 728, a fall prevention inflatable cell foranti-eschar mattresses has already been proposed. This cell comprisestwo outer sheets welded on the periphery thereof so as to form aninflatable housing, and which are fastened by circular welding spots toan inner sheet making it possible to limit the expansion of the housing.Once inflated, the housing includes a support surface having abasin-shaped fall prevention profile with raised ends.

With this type of cell including circular welding spots, there is,however, a risk, under the repeated effects of inflation/deflationcycles, of two adjacent individual cells sliding vertically, relative toeach other, resulting in poor alignment and positioning of the cells,which is detrimental to the proper operation of the anti-escharmattress.

The positioning flaw is even more pronounced in the case whereinflatable cells with horizontal oblong welds are used as described andillustrated in FIGS. 2 and 3 of U.S. Pat. No. 5,109,560. With this typeof cells, to prevent this positioning flaw, one is thus forced to fasteneach individual cell on a support, which complicates the structure andproduction of the anti-eschar mattress.

BRIEF DESCRIPTION OF THE INVENTION

One aim of the invention is to propose a new inflatable cell foranti-eschar mattresses making it possible to obtain proper operation, indynamic mode, while preventing the aforementioned risks of sliding andpoor positioning of the cell, relative to an adjacent cell, duringrepeated inflation/deflation cycles, and without it being necessary tofasten the cell on a support.

The first object of the invention is therefore an inflatable cell foranti-eschar mattresses defined in claim 1. This cell comprises aninflatable housing having an elongate shape and two main opposed sidesurfaces, as well as several oblong welds that have a main longitudinalaxis substantially perpendicular to the main longitudinal axis of thehousing, which are spaced apart along the length of the housing, andwhich connect two main opposed side surfaces of the housing together.

Another aim of the invention is to propose a new inflatable cell foranti-eschar mattresses that makes it possible to reduce, for bedriddenpeople, both the risk of eschar formation and accidental fall risks.

The second aim of the invention is therefore an inflatable cell foranti-eschar mattresses, said cell comprising an inflatable housinghaving an elongate shape and two main opposed side surfaces, as well asan upper surface which, in the inflated state of the housing, forms anupper support surface; the two main opposed side surfaces of the cellare welded to each other on at least three sides of their peripheryusing at least one lower longitudinal weld and two side welds, and saidlower longitudinal weld has a curve profile that is made so that whenthe housing is inflated, the support surface is deformed so as to have abasin-shaped fall prevention curve profile with raised ends.

The third object of the invention is an inflatable cell for anti-escharmattresses, said cell including an inflatable housing having an elongateshape and two main opposed side surfaces, as well as an upper surfacewhich, in the inflated state of the housing, forms an upper supportsurface; said housing is either (i) formed by a sheet folded in twolengthwise, and welded on three sides of its periphery using a lowerlongitudinal weld and two side welds, and the support surface being freefrom welds, or (ii) formed by two separate sheets welded to each otherover the entire periphery thereof using at least four welds: a lowerlongitudinal weld, two side welds, and an upper longitudinal weld, saidcell including one or more additional welds that are spaced apart alongthe length of the housing, and that make it possible to connect the twomain opposed side surfaces of the housing to each other, the distance(e₁) between each additional end weld and the adjacent side weld of thehousing, measured along the longitudinal axis of the housing, beinggreater than or equal to the distance (e₂) between said additional endweld and (i) the upper bend line of the sheet forming the housing, or(ii) the upper longitudinal weld, such that when the housing isinflated, the support surface (SP) is deformed so as to have abasin-shaped fall prevention curve profile with raised ends.

The fourth object of the invention is an inflatable cell for anti-escharmattresses, said cell includes an inflatable housing having an elongateshape and two main opposed side surfaces, an upper surface that forms anupper support surface when the housing is inflated, and one or severaloblong welds, the main longitudinal axis of which is substantiallyparallel to the main longitudinal axis of the housing, and which make itpossible to connect the two main opposed side surfaces of the housing toeach other, so as to define, in the housing, at least two superimposedinflation chambers that communicate with each other; the upper supportsurface of the deflated housing has a substantially rectilinear profileover the entire length of the housing, and the oblong weld(s) are madeso that when the housing is inflated, the support surface is deformed soas to have a basin-shaped fall prevention curve profile with raisedends.

The invention also relates to an anti-eschar mattress comprising aplurality of the previously cited inflatable cells, which are positionedtransversely to the longitudinal axis of the mattress, and which arejuxtaposed along said longitudinal axis.

BRIEF DESCRIPTION OF THE FIGURES

Other features and advantages of the invention will appear more clearlyupon reading the following detailed description of several preferredembodiments of the invention, this description being provided as anon-limiting and non-exhaustive example of the invention, and inreference to the appended drawings, in which:

FIG. 1 is a perspective illustration of an inflatable cell foranti-eschar mattresses, made according to a first alternativeembodiment,

FIG. 2 is a diagrammatic view in transverse cross-section of the cell ofFIG. 1 in cutting plane II-II,

FIG. 3 is a diagrammatic and partial top view of the cell of FIG. 1,

FIG. 4 is a diagrammatic flattened lateral view of the cell of FIG. 1(deflated state),

FIG. 5 is a diagrammatic flattened front view of an inflatable cell foranti-eschar mattresses, done according to a second alternativeembodiment,

FIG. 6 is a diagrammatic flattened front view of an inflatable cell foranti-eschar mattresses, done according to a third alternativeembodiment,

FIG. 7 is a perspective illustration of a cell of an anti-escharmattress, inflated and done according to a fourth alternative embodimentof the invention,

FIG. 8 is a flattened diagrammatic illustration of the cell of FIG. 7 inthe deflated state,

FIG. 9 is a diagrammatic transverse cross-section of the cell of FIG. 7in plane IX-IX,

FIG. 10 is a top view of the cell of FIG. 7,

FIG. 11 is a transverse cross-section in plane XI-XI of the cell of FIG.8,

FIG. 12 is a longitudinal cross-section in plane XII-XII of the cell ofFIG. 6,

FIG. 13 is a diagrammatic side view of a set of cells according to theinvention that are juxtaposed, so as to form an anti-eschar mattress,

FIG. 14 is a diagrammatic side view of a set of cylindrical cells of theprior art that are juxtaposed, so as to form an anti-eschar mattress,

FIG. 15 is a diagrammatic flattened side view of a cell in the deflatedstate, done according to a fifth alternative embodiment of theinvention,

FIG. 16 is a diagrammatic flattened front view of an inflatable cell foranti-eschar mattresses, done according to a sixth alternative embodimentof the invention,

FIG. 17 is a diagrammatic flattened front view of an inflatable cell foran anti-eschar mattress, done according to a seventh alternativeembodiment of the invention,

FIG. 18 shows a cell, in the inflated state, made according to an eighthalternative embodiment of the invention,

FIG. 19 is a diagrammatic side view of the cell of FIG. 18.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 and 4 show an inflatable individual cell 1 for an anti-escharmattress, according to a first alternative embodiment of the invention.In FIG. 1, the cell 1 is inflated. In FIG. 4, the cell 1 is shown flat,deflated.

This cell 1 includes an inflatable housing 2 having an elongate shapeand a longitudinal main axis 2 a. In the illustrated example, thishousing 2 is made up of a substantially rectangular sheet 20 made from aheat-weldable material, and for example polyurethane. When the cell isdeflated, this sheet 20 is folded over in two lengthwise along asubstantially rectilinear longitudinal upper bend line 20 a (diagrammedby a broken line in FIG. 3). In FIG. 3, the two longitudinal edges ofthe sheet 20 that are folded one on top of the other are referenced 20b, and the two side edges of the sheet 20 that are folded one on top ofthe other are referenced 20 c.

The folded sheet 20 is heat-welded on three sides of its periphery usinga lower longitudinal weld 4 (opposite the upper weld 20 a) with lengthL₂, smaller than length L₁ of the sheet 20, and two side welds 5 thatextend said longitudinal weld 4 at both of its two, and that extend tothe upper longitudinal bend line 20 a of the sheet 20.

The two surfaces 20 d, 20 e of the sheet 20 (FIGS. 1 and 4) that arefolded one on top of the other form the two main side surfaces of theinflatable housing 2.

The lower longitudinal weld 4 has a particular curved bowed profilewhereof the apex 4 a is oriented towards the upper bend line 20 a. Inreference to FIG. 4, the distance H₂ between this apex 4 a of the weld 4and the upper bend line 20 a that corresponds to the upper longitudinaledge of the deflated housing 2, is smaller than the height H₁ of theside welds 5. Dimension H₂ corresponds to the height at the center ofthe deflated housing 2, and dimension H₁ corresponds to the height atthe ends of the deflated housing 2.

The housing 2 also contains an inner sheet 6 made from a heat-weldablematerial, and for example polyurethane, that has been positioned betweenthe two surfaces 20 d, 20 e of the sheet 20 folded one on top of theother, before heat-welding of the two surfaces 20 d, 20 e.

Each main surface 20 d, 20 e of the housing 2 is fastened to the innersheet 6, using vertical oblong heat welds 7A and 7B, with mainlongitudinal axis 7 a, length L₃ and width l₃ (L₃>l₃). The mainlongitudinal axis 7 a of the welds 7A, 7B is substantially perpendicularto the main longitudinal axis 2 a of the housing 2, and the welds 7A, 7Bare spaced apart along the length of the housing 2. Each weld 7A, 7Bincludes a peripheral edge 7 b forming a closed oblong contour.

Preferably, for better solidity, at a weld 7A or 7B, the surface 20 d or20 e of the sheet 20 is welded on the entire surface situated inside theperipheral edge 7 b. In another alternative, the surface 20 d or 20 e ofthe sheet 20 can be welded only along a thin weld corresponding to saidoblong peripheral contour 7 b.

In reference to FIGS. 1, 3 and 4, the oblong heat welds 7A correspond tothe welds of the surface 20 d of the housing 2 with the inner sheet 6,and the oblong heat welds 7B (in broken lines in FIGS. 1 and 4)correspond to the welds of the other surface 20 e of the housing 2 withthe inner sheet 6. These welds 7A and 7B alternate along the length(direction Y) of the housing 2.

The welds 4 and 5 and the oblong welds 7A, 7B are for example made byhigh frequency welding.

In the alternative of FIG. 4, the welds 7A and 7B are all identical.This feature is not, however, essential.

In the alternative of FIG. 4, the welds 7A (7B, respectively) of asurface 20 d (20 e, respectively) are substantially equidistant alongthe longitudinal axis 2 a of the cell. This feature is not, however,essential.

The invention is not limited to the particular number of welds 7A, 7B ofFIG. 4, the cell according to the invention being able to include morewelds 7A, 7B or fewer welds 7A, 7B than the alternative of FIG. 4. Thenumber of welds 7A, 7B and their spacing depends in particular on thelength of the inflatable housing.

In one 20 d of the main surfaces of the housing 2, an opening 3 isformed to allow air to pass. The cell 1 includes an inflation stem 8,for example made from plastic, that can integrate a valve, and thatallows fast inflation and deflation of the housing 2. This stem 8 isfastened, for example by gluing, on the housing 2 at the opening 3. Thisstem 8 is intended to be connected to a compressor (not shown), forexample using a flexible tubing to allow the inflation and deflation ofthe housing 2 of the cell 1.

When the cell is inflated, the upper surface of the inflated cell thatextends on either side of the bend line 20 a forms an upper supportsurface SP (FIGS. 1 and 2) with which the body of the bedridden personcomes into contact.

In the particular alternative of FIGS. 1 to 4, this support surface SPis for example free from welds, and is advantageously smooth.

To make an anti-eschar and fall prevention mattress M according to theinvention, a plurality of cells 1 are juxtaposed against each otheralong longitudinal axis X, each cell 1 being positioned perpendicular(axis Y) to this longitudinal axis X, and the main surface 20 d of acell being in contact with the main surface 20 e of an adjacent cell.

Also, preferably fastened on the housing 2 of the cell is a means 9, forexample snap fasteners, making it possible, if necessary, to quicklyassemble two adjacent cells 1 together, when the mattress is formed. Thecells 1 are placed on a support plane such as a box spring, withoutbeing fastened to said planar support.

In a known manner, when the mattress M is used, all of the cells 1 arenot inflated at the same time, but are inflated and deflatedindividually according to a programmed cycle, so as to cyclically modifythe compression points on the body of the person lying on the mattress,which makes it possible to reduce the risk of eschar formation.

When a cell is inflated, each portion 20 f of the main surface 20 d (20e, respectively) of the housing 2 situated between two adjacent welds 7A(7B, respectively) advantageously forms, owing to the implementation ofvertical oblong welds 7A (7B, respectively), a mat whereof the outersurface is only convex over the entire height of the housing 2, and doesnot include a concave portion, unlike what can be obtained with a cellaccording to FIG. 1 of application FR 2 883 728, for example, or fromthe cells according to FIGS. 2 and 3 of U.S. Pat. No. 5,109,560. Therisks of vertical sliding and poor height positioning of a cell 1relative to an adjacent cell are thus avoided during repeatedinflation/deflation cycles of the cells of the mattress.

Preferably, but not necessarily, the oblong welds 7A, 7B aresubstantially centered between the lower longitudinal weld 4 and theupper longitudinal edge of the deflated housing 2, i.e. in thealternative of FIG. 4, the upper weld 20 a.

The length L₃ of each weld 7A, 7B is chosen so as in particular toobtain the formation of the aforementioned mats 20 f with the solelyconvex surface. Preferably, but not necessarily, the length L₃ of eachweld 7A, 7B is at least equal to 30% of the maximum height H₁ of thedeflated housing 2 (FIG. 4) and/or preferably at least equal to 50% ofthe height H₄ of the inner sheet 6 serving to limit displacement.

In the alternative of FIGS. 1 to 4, the inner sheet 6 serves to limitthe expansion of the housing 2 in direction X, which is perpendicular tothe two main surfaces 20 d, 20 e of the housing 2, and thereby makes itpossible to limit the width of the inflated housing 2. It also makes itpossible, combined with the oblong welds 7A, 7B, to obtain a cell 1 thatis mechanically robust, and whereof the welds 7A, 7B are not alteredafter intensive use.

In another alternative embodiment, the cell could be provided without aninner sheet 6 and the main surfaces 20 d, 20 e could be welded to eachother directly using vertical oblong welds 7A, 7B in a manner comparableto the cell of FIG. 7 described below whereof the two main surfaces 20d, 20 e are welded together using horizontal oblong welds 7.

In the alternative of FIGS. 1 to 4, owing to the use of a bowed lowerlongitudinal weld 4 with a height H₂ smaller than the height H₁, whenthe housing 2 is inflated, the upper support surface SP isadvantageously automatically deformed so as to have a curved fallprevention profile forming a basin oriented along the longitudinal axis2 a of the cell with raised ends 20 g (FIG. 1). This basin-shapedprofile with raised ends 20 g advantageously makes it possible to hinderthe sliding in direction Y of a person lying on a mattress M includingcells juxtaposed in direction X, and thus to laterally stabilize saidperson in a central position on the mattress M. The risk of accidentalfall is thereby greatly reduced.

The larger the height difference ΔH between the heights H₁ and H₂(ΔH=H₁−H₂), the greater the deformation of the basin-shaped supportsurface SP. To obtain an effective fall prevention effect, the heightdifference ΔH between the heights H₁ and H₂ is preferably, but notnecessarily at least equal to 3 cm, and still more preferably at leastequal to 5 cm.

The longitudinal weld 4 may have another curve profile making itpossible to obtain the basin-shaped fall prevention profile for thesupport surface SP, when the housing 2 is inflated. In particular, thelongitudinal weld 4 could have another curve profile making it possibleto obtain a height H₂ at the center of the housing smaller than theheight H₁ at the ends of the housing 2.

In the particular embodiment of FIG. 4, the apex 4 a of the lowerlongitudinal weld 4 is substantially centered relative to the housing 2along the longitudinal axis 2 a of the housing. This feature, althoughpreferable, is not, however, essential.

In the alternative of FIG. 4, the smallest distance e₁ between each endweld 7A and the adjacent side weld 5 of the housing, measured along thelongitudinal axis 2 a of the housing, is greater than or equal to, andpreferably greater than, the smallest distance e₂ between said weld 7Aand the upper bend line 20 a of the housing 2. This advantageouslyresults in increasing the raising of the ends 20 g of the basin-shapedsupport surface SP, when the housing 2 is inflated. In FIG. 4, thedistance e1 is substantially equal to the distance e2. If one wishes tomore substantially increase the raising of the ends 20 g of the supportsurface SP, one will preferably use a distance e1 greater than thedistance e2, as is done for example for the alternative of FIG. 16described below.

This dimensional characteristic (e1≧e2) is, however, optional to obtainthe fall prevention profile, when a lower weld 4 having the curveprofile of FIG. 4 is used. As an example, FIG. 5 shows anotheralternative embodiment in which the distance e1 is smaller than thedistance e2, and which nevertheless makes it possible to obtain abasin-shaped fall prevention profile for the support surface SP of thecell, owing to the use of the curved longitudinal lower weld 4.

The table below provides, as an example of an embodiment, specificvalues (in mm) for the main dimensions of the cells shown in FIGS. 4 and5. These specific values are not limiting for the invention. For thesespecific dimensions, the inner sheet 6 used is for example a rectangularsheet with a length L₄ of 950 mm, a width H₄ of 180 mm, and a thicknessof 0.2 mm.

FIG. L1 L2 H₁ H₂ L₃ l₃ e₁ e₂ 4 990 910 300 250 102 20 90 90 5 990 910300 250 102 20 70 90

FIG. 6 shows another alternative embodiment, which makes it possible toobtain a support surface having a basin-shaped fall prevention profile.In particular, this alternative of FIG. 6 uses a lower longitudinal weld4 having a curve profile that makes it possible to obtain a supportsurface SP with a basin-shaped fall prevention profile, when the housing2 is inflated.

More particularly, the alternative of FIG. 6 differs from thealternative of FIG. 4 mainly by the use of pairs of circular welds 7′A(7′B, respectively) replacing the oblong welds 7A (7B, respectively).Unlike the alternative of FIG. 4, this alternative does not, however,make it possible to obtain the aforementioned mats 20 f with a solelyconvex surface.

FIGS. 7 and 8 show an individual inflatable cell 1′ for an anti-escharmattress, according to another alternative embodiment of the invention.In FIG. 7, the cell 1 is inflated. In FIG. 8, the cell 1′ is shown flatand deflated.

Identically to the cell 1 of FIG. 1, this cell 1′ includes an inflatablehousing 2 having an elongate shape and a longitudinal main axis 2 a.This housing 2 is made up of a substantially rectangular sheet 20 madefrom a heat-weldable material, and for example polyurethane. This sheet20 is folded over in two lengthwise following a longitudinal upper bendline 20 a. Out of a concern for simplification, the shared elementsbetween this cell 1′ of FIG. 6 and the cell 1 of FIG. 1 use the samereferences.

The folded sheet 20 is heat-weldable on three sides of the peripherythereof using a lower longitudinal weld 4′ with length L₂, smaller thanlength L₁ of the sheet 20, and two side welds 5 that extend saidlongitudinal weld 4′ at both ends thereof, and which extend to the upperlongitudinal bend line 20 a of the sheet 20.

Unlike the cell 1 of FIGS. 1 and 3, the lower weld 4′ is not curved, butrather is substantially rectilinear.

Unlike the cell 1 of FIGS. 1 and 3, the cell 1′ does not have an innersheet 6 serving to limit displacement, and the two main side surfaces 20d, 20 e of the inflatable housing 2 are heat-welded directly to eachother using an oblong weld 7, with longitudinal axis 7 a, length L₃ andwidth l₃ (L₃>l₃). Each weld 7 includes a peripheral edge 7 b forming aclosed oblong contour.

Preferably, for better solidity, at a weld 7, the two surfaces 20 d, 20e of the sheet 20 are welded over the entire surface situated inside theperipheral edge 7 b. In another alternative, the two surfaces 20 d, 20 eof the sheet 20 can be welded only along a thin weld corresponding tosaid oblong peripheral contour 7 b.

The welds 7 are oriented so that the main longitudinal axis 7 a thereofis substantially parallel to the main longitudinal axis 2 a of thehousing 2. The welds 7 are also positioned relative to each other spacedapart and aligned along the main longitudinal axis 2 a of the housing 2.

The welds 7 make it possible to define, in the housing 2, twosuperimposed chambers, i.e. a lower chamber 2 b and an upper chamber 2 c(FIG. 10), which extend over the entire length L₂ of the housing 2, andwhich communicate with each other owing to spaces E (FIG. 7 and FIG. 11)between the welds 7.

During inflation of the housing 2, the air that is blown into the lowerchamber 2 b, via the inflation stem 8, spreads in said chamber 2 b and,owing to the spaces E (FIGS. 7 and 11) between the welds 7, this airalso easily penetrates the upper chamber 2 c of the housing 2 whilebeing advantageously distributed over the entire length of the housing2. Once the housing 2 is inflated with air, said housing 2 forms twosuperimposed air cushions C1, C2 (FIG. 11) corresponding respectively tothe two chambers 2 b and 2 c defined by the weld 7.

Conversely, when the housing 2 is deflated, the air contained in theupper chamber 2 c can be evacuated quickly through the stem 8 by passingthrough the lower chamber 2 b, which allows fast deflation of the twocushions C1 and C2.

In the alternative embodiment of FIGS. 7 and 8, the welds 7 areidentical and the distances d between two adjacent welds 7, measuredalong the longitudinal axis 2 a of the housing, are identical. Inanother alternative, the welds 7 can have a different oblong shape, andcan also not be identical; the spacing d between welds 7 is notnecessarily constant. In the alternative embodiment of FIGS. 7 and 8,four aligned and spaced welds 7 are used. This particular number ofwelds 7 is not limiting.

In the alternative shown in FIGS. 7 and 8, the weld 7 is madesubstantially at mid-height H of the housing 2, such that the cushionsC1, C2 advantageously have substantially the same volume. In anotheralternative of the invention, the height position of the weld 7 maynevertheless be different, and the volumes of the two cushions C1 and C2may thus be different.

It is understood that the distance d between two adjacent welds 7influences the ability of the air to pass more or less easily from onechamber 2 b to the other 2 c, and thereby influences the ease and speedof inflation of the cushions C1 and C2. The larger this distance dbetween two welds 7, the easier the inflation and deflation of the twocushions C1, C2. Conversely, the length of the welds 7 must be longenough to obtain a mechanical strength of the welds 7 that is bothsufficient and reliable over time. It is therefore appropriate to selectthe length L₃ of the welds 7 and the distance d between welds 7 takingthese two contradictory constraints into account. In the alternativeembodiment of FIGS. 1 and 2, this distance d between two adjacent welds7 is slightly larger than the length L₃ of a weld 7. In anotheralternative, this distance d between two adjacent welds 7 could be equalto or smaller than the length L₃ of a weld 7. Preferably, but notnecessarily, the total length of the welds 7 (sum of the lengths L₃) isat least equal to 40% of the total length L₂ of the inflation chambers 2b, 2 c.

For reasons of vertical stability of the cell during inflation/deflationoperations, it is preferable for the housing 2 of the cell 1 to includeonly two superimposed chambers 2 b, 2 c corresponding to thesuperimposed cushions C1 and C2. However, in the context of theinvention, it is also possible to consider making a cell including atleast two oblong welds 7, which are spaced apart along the height H ofthe cell, so as to define at least three superimposed inflation chambers(or three superimposed air cushions), each chamber communicating withthe adjacent chamber via spaces between welds.

FIG. 13 diagrammatically shows an anti-eschar mattress M according tothe invention made using a plurality of cells 1′ that are juxtaposedagainst each other along the longitudinal axis X of the mattress, eachcell 1′ being positioned perpendicular to said longitudinal axis X(longitudinal axis 2 a of each cell 1 perpendicular to axis X).

In a known manner, when the mattress M is used, all of the cells 1′ arenot inflated at the same time, but are inflated and deflatedindividually according to a programmed cycle, so as to cyclically anddynamically modify the compression points on the body of the personlying on the mattress, which makes it possible to reduce the risks ofeschar formation, and makes the bedridden person feel a dynamic reliefeffect. In this particular example of FIG. 13, but non-limitingly,during each cycle, every other cell 1 is inflated and the remainingcells 1 are deflated. This particular dynamic mode corresponds to a useof the mattress for anti-eschar preventive care with 50% lift. It isalso possible in another dynamic mode to divide the mattress intoseveral groups of n cells (n≧3), and during successive cycles todeflate, in each group of cells successively, one cell out of the ncells, the other cells in the group being inflated. This dynamic modecorresponds to a use of the mattress for curative care. In thisparticular dynamic mode, the use of cells according to the inventionallows better vascularization of the cutaneous tissue of the bedriddenperson.

The weld 7 of each cell 1′ advantageously makes it possible to limit thelateral expansion of the cell 1, i.e. in the longitudinal direction X ofthe mattress, and advantageously to obtain a cell 1 that, once inflated,has an upper support surface SP with a small maximum width L_(max)(FIGS. 10, 11) and a height H′ when inflated that is larger than saidmaximum width L_(max). Advantageously, the upper support surface SP isfree from welds.

By using cells 1′ whereof the maximum width L_(max) of the supportsurface SP of the inflated cell is small, it is advantageously possible,for a same mattress length M, to use a larger number of juxtaposedcells, compared to inflatable cells C, for example (FIG. 14), requiringthe same volume of inflation air and forming cylindrical rolls wheninflated. During each cycle, the width e of the spaces between twoadjacent inflated cells 1 is advantageously reduced, and the totalcontact surface between the bedridden person and the support surfaces SPof the inflated cells is increased. A better distribution is thusobtained of the weight of the bedridden person over the entire length ofthe mattress M of cells 1′, and excessive localized compressions areavoided on the bedridden person. In this way, unlike the prior artsolution shown in FIG. 14, the risks of “tourniquet effect” areadvantageously eliminated at the bearing zones of the body on the cells1. Moreover, owing to the use of at least two superimposed air cushionsC1, C2 on each cell, the height H′ of the inflated cell 1 is increased,and one significantly improves the comfort of the bedridden person andthe eschar treatment.

It should be noted that the maximum width L_(max) of an inflated cell 1′must preferably also not be too small. Indeed, if this width L_(max) istoo small, the total contact surface in each cycle between the bedriddenperson and the support surfaces SP of the inflated cells can become toolarge, and eliminate the dynamic relief effect for the bedridden person.In practice, it is preferable for this total contact surface to bebetween 50% and 75%.

For information and non-limitingly, the cell 1′ according to theinvention is preferably designed to have a maximum width L_(max) wheninflated between 6 cm and 9 cm. More particularly, in one preferredembodiment, the cell 1′ has been designed to have an optimized maximumwidth L_(max) in the vicinity of 7 cm to 8 cm.

In reference to FIG. 7, according to another advantageous feature of theinvention, the two main side surfaces 20 d, 20 e of the housing 2 arewelded to each other so that once inflated, the housing 2 includes anupper support surface SP having a basin-shaped fall prevention profilewith raised ends 20 g. These raised ends 20 g advantageously make itpossible to hinder lateral sliding (FIG. 7/axis Y) by a person lying onthe mattress M, and to laterally stabilize the person in a centralposition on the mattress M. Accidental fall risks are thereby verysignificantly reduced.

In the particular alternative embodiment shown in FIGS. 7 and 8, whendeflated, the upper support surface SP of the housing 2 is substantiallyrectilinear (FIG. 7). The two main side surfaces 20 d, 20 e of thehousing 2 are welded together so that the inflation of the housing 2causes a deformation of the support surface SP of the housing 2 in theform of a basin with raised ends 20 g (FIG. 7). To obtain thisdeformation of the housing 2, the two end welds 7 should be carefullypositioned as close as possible to the side welds 5, so that when thehousing 2 is inflated, these end welds 7 exert, relative to the sidewelds 5, a traction making it possible to raise the upper ends 20 g, asillustrated in FIG. 7. In this alternative, this is obtained inparticular by providing, between each end weld 7 and adjacent side weld5, a distance e₁ measured along the longitudinal axis 2 a of the housingthat is equal to or slightly larger than the distance e₂ (measuredperpendicular to the longitudinal axis 2 a) between said weld 7 and theupper bend line 20 a of the sheet 20 forming the housing 2.

Specific Example of Sizing of the Cell 1′

As a non-limiting example of the invention, in one specific embodiment,the cell 1′ had the following main dimensions:

L₁=100 cm; L₂=90 cm; L₃=10 cm; l₃=1.8 cm; d=11 cm; H=26 cm; H′=18 cm;H″=23 cm; L_(max)=8 cm; L_(min)=7 cm; e₁=11.5 cm; e₂=11 cm.

FIG. 15 shows another alternative embodiment of a cell 1′ according tothe invention including a single oblong weld 7.

FIG. 16 shows another alternative embodiment of a cell 1″ according tothe invention, which, comparably to the alternative of FIG. 7, includesan oval oblong weld 7 whereof the longitudinal axis 7 a is substantiallyparallel to the longitudinal axis 2 a of the cell, and which differsfrom the alternative of FIGS. 7 and 8 mainly by the use of a lowerlongitudinal weld line 4 that has a curve profile similar to that of thealternative of FIG. 1, so as to obtain the basin-shaped fall preventionprofile for the support surface SP. In this alternative, the distance e1is also much larger than the distance e2 so as to increase the raisingeffect of the ends 20 g of the housing 2 during inflation thereof, andto improve the fall prevention effect.

FIG. 17 shows another alternative embodiment of a cell 1′″ according tothe invention, which differs from the cell of FIG. 16 only by the use oftwo separate sheets 20 d, 20 e, instead of a single sheet 20 folded intwo. These two separate sheets 20 d, 20 e are welded together over theentire periphery thereof using four welds: the three welds 4, 5previously described, and an additional upper longitudinal weld 11,which replaces the bend line 20 a. When the housing 2 of this cell ofFIG. 17 is inflated, the support surface SP extends on either side ofthis upper weld 11.

Similarly to this alternative of FIG. 17, the cells of FIGS. 1, 5, 6, 7and 15 previously described may also be modified so as to replace thesheet 20 folded in two (with upper bend line 20 a) with two separatesheets 20 d, 20 e welded along a closed contour by a lower longitudinalweld 4 (or 4′) extended at both ends thereof by two side welds 5, whichthemselves are connected to each other by an upper longitudinal weld 11.

FIG. 18 shows another alternative embodiment of a cell according to theinvention including an inflatable housing 2 having, when inflated, twomain side surfaces 20 d, 20 e, an upper support surface SP, a lowerbottom surface F, and two end surfaces F′. This cell also has asubstantially rectangular inner sheet 6′, which makes it possible tolimit the expansion of the thickness of the cell (direction X). The mainsurface 20 d of the cell is welded to one of the longitudinal edges ofthe inner sheet 6′ using an oblong longitudinal weld 7. The other mainsurface 20 e of the cell is welded to the other longitudinal edge of theinner sheet 6′ using an oblong longitudinal weld 7.

In this alternative, the housing of the cell also includes outerreinforcing welds S (shown in thicker lines) that, at the two endsurfaces F′ of the cell, have a

-shaped profile and allow the cell to be shaped. When the housing of thecell is inflated, the inner sheet 6′ is substantially horizontal, i.e.substantially perpendicular to the two main side surfaces 20 d, 20 e,and the housing forms two superimposed cushions C1, C2.

The oblong side welds 7 do not extend to the two end surfaces F′ andeach have a length L₃ small enough that when the housing is inflated,the upper support surface SP is deformed so as to have a basin-shapedfall prevention profile with raised ends 20 g (smaller volume at thecenter of the housing than the volume of the housing at its ends). Moreparticularly, to obtain this fall prevention profile, the distance e1separating each end of a longitudinal weld 7 from the adjacent endsurface F′ and that is measured along the longitudinal axis 2 a of thehousing, is greater than or equal to the distance e₂ separating said endof the weld 7 and the support surface SP, and which is measured alongdirection (Z) perpendicular to the longitudinal axis 2 a.

The cell of FIGS. 18 and 19 can also be modified by replacing alongitudinal weld 7 with several shorter longitudinal welds 7 spacedapart in the longitudinal direction 2 a of the cell, in a mannercomparable to the alternative previously described in FIG. 7.

1. An inflatable cell for anti-eschar mattresses, said cell comprises aninflatable housing having an elongate shape and two main opposed sidesurfaces, as well as several oblong welds whereof the main longitudinalaxis is substantially perpendicular to the main longitudinal axis of thehousing, which are spaced apart along the length of the housing, andwhich connect two main opposed side surfaces of the housing together. 2.The cell according to claim 1, comprising an inner sheet that ispositioned between the two main surfaces using said oblong welds, andwhich makes it possible to limit the expansion of the cell.
 3. The cellaccording to claim 2, wherein the length (L₃) of each oblong weld is atleast equal to 50% of the height (H₄) of the inner sheet.
 4. The cellaccording to claim 1, wherein the two main opposed side surfaces arewelded directly to each other using said oblong welds.
 5. The cellaccording to claim 1, comprising an upper surface that, when the housingis inflated, forms an upper support surface, wherein the two main sidesurfaces of the cell are welded together over at least three sides ofthe periphery thereof using at least one lower longitudinal weld and twoside welds, said lower longitudinal weld having a curve profile made sothat when the housing is inflated, the support surface is deformed so asto have a basin-shaped fall prevention curve profile with raised ends.6. The cell according to claim 5, wherein said lower longitudinal weldhas a bowed curve profile whereof the apex is oriented towards thesupport surface, so that when the housing is inflated, the supportsurface is deformed so as to have a basin-shaped fall prevented curveprofile with raised ends.
 7. The cell according to claim 6, wherein whenthe housing is deflated, the height H₁ between the apex of said lowerlongitudinal weld is smaller than the height H₂ at the ends of thehousing.
 8. The cell according to claim 5, wherein said lowerlongitudinal weld has a curve profile such that the height at the centerH₁ of the deflated housing is smaller than the height H₂ at the ends ofthe deflated housing.
 9. The cell according to claim 7, wherein theheight difference ΔH (ΔH=H₁−H₂) between the heights H₁ and H₂ is atleast equal to 3 cm, and preferably at least equal to 5 cm.
 10. The cellaccording to claim 1, wherein said housing is made up of a sheet foldedin two lengthwise, and welded on three sides of the periphery thereofusing at least one lower longitudinal weld and two side welds, thesupport surface being free of welds.
 11. The cell according to claim 10,wherein the distance (e₁) between each oblong end weld and the adjacentside weld of the housing, measured along the longitudinal axis of thehousing, is greater than or equal to the distance (e₂) between saidoblong end weld and the upper bend line of the sheet forming thehousing.
 12. The cell according to claim 1, wherein the housing is madeup of two separate sheets welded together over the entire peripherythereof using at least four welds: a lower longitudinal weld, two sidewelds, and an upper longitudinal weld.
 13. The cell according to claim12, wherein the distance (e₁) between each oblong end weld and theadjacent side weld of the housing, measured along the longitudinal axisof the housing, is greater than or equal to the distance (e₂) saidoblong end weld and the upper weld line.
 14. The cell according to claim1, wherein the upper support surface of the deflated housing has asubstantially rectilinear profile over the entire length of the housing.15. The cell according to claim 1, wherein the oblong welds aresubstantially centered over the height (H₁) of the housing of the cell.16. The cell according to claim 1, wherein the length (L₃) of eachoblong weld is at least equal to 30% of the maximum height (H₁) of thedeflated housing.
 17. An inflatable cell for anti-eschar mattresses,said cell comprising an inflatable housing having an elongate shape andtwo main opposed side surfaces, as well as an upper surface which, inthe inflated state of the housing, forms an upper support surface, thetwo main opposed side surfaces of the cell being welded to each other onat least three sides of their periphery using at least one lowerlongitudinal weld and two side welds, and said lower longitudinal weldhaving a curve profile that is made so that when the housing isinflated, the support surface is deformed so as to have a basin-shapedfall prevention curve profile with raised ends.
 18. The cell accordingto claim 17, wherein said lower longitudinal weld has a bowed curveprofile whereof the apex is oriented towards the support surface, sothat when the housing is inflated, the support surface is deformed so asto have a basin-shaped fall prevention curve profile with raised ends.19. The cell according to claim 18, wherein when the housing isdeflated, the height H₁ between the apex of said lower longitudinal weldis smaller than the height H₂ at the ends of the housing.
 20. The cellaccording to claim 17, wherein said lower longitudinal weld has a curveprofile such that the height at the center H₁ of the deflated housing issmaller than the height H₂ at the ends of the deflated housing.
 21. Thecell according to claim 19, wherein the height difference ΔH (ΔH=H₁−H₂)between the heights H₁ and H₂ is at least equal to 3 cm, and preferablyat least equal to 5 cm.
 22. The cell according to claim 17, comprisingone or more additional welds that make it possible to connect the twomain opposed side surfaces of the housing together.
 23. The cellaccording to claim 22, wherein the additional weld(s) are oblong. 24.The cell according to claim 23, wherein the additional oblong weld(s)are oriented so that their main longitudinal axis is substantiallyparallel to the main longitudinal axis of the housing, and define atleast two superimposed inflation chambers that communicate with eachother.
 25. The cell according to claim 17, comprising several additionaloblong welds, whereof the main longitudinal axis is substantiallyperpendicular to the main longitudinal axis of the housing, which arespaced apart along the length of the housing, and which make it possibleto connect the two main opposed side surfaces of the housing together.26. The cell according to claim 25, wherein the length (L₃) of eachadditional oblong weld is at least equal to 30% of the maximum height(H₁) of the deflated housing.
 27. The cell according to claim 22,comprising an inner sheet positioned between the two main side surfacesof the housing, which is welded to said main side surfaces via saidadditional welds, and which makes it possible to limit the expansion ofthe cell.
 28. The cell according to claim 25, wherein the length (L₃) ofeach additional oblong weld is at least equal to 50% of the height (H₄)of the inner sheet.
 29. The cell according to claim 22, wherein the twomain opposed side surfaces are welded together directly via saidadditional welds.
 30. The cell according to claim 22, wherein theadditional welds are substantially centered on the height of the housingof the cell.
 31. The cell according to claim 17, wherein said housing ismade up of a sheet folded in two lengthwise, and welded on three sidesof the periphery thereof via the lower longitudinal weld and said sidewelds, the support surface being free of welds.
 32. The cell accordingto claim 31, wherein the distance (e₁) between each additional end weldand the adjacent side weld of the housing, measured along thelongitudinal axis of the housing, is greater than or equal to thedistance (e₂) between said additional end weld and the upper bend lineof the sheet forming the housing, so that when the housing is inflated,the support surface is deformed so as to have a basin-shaped fallprevention curve profile with raised ends.
 33. The cell according toclaim 17, wherein the housing is formed by two separate sheets weldedtogether on the entire periphery thereof via at least four welds: alower longitudinal weld two side welds, and an upper longitudinal weld.34. The cell according to claim 33, wherein the distance (e₁) betweeneach additional end weld and the adjacent side weld of the housing,measured along the longitudinal axis of the housing, is greater than orequal to the distance (e₂) between said additional end weld and theupper weld, so that when the housing is inflated, the support surface isdeformed so as to have a basin-shaped fall prevention curve profile withraised ends.
 35. The cell according to claim 17, wherein the uppersupport surface of the deflated housing has a substantially rectilinearprofile over the entire length of the housing.
 36. An inflatable cellfor anti-eschar mattresses, said cell including an inflatable housinghaving an elongate shape and two main opposed side surfaces, as well asan upper surface which, in the inflated state of the housing, forms anupper support surface, said housing being either (i) formed by a sheetfolded in two lengthwise, and welded on three sides of its peripheryusing a lower longitudinal weld and two side welds, and the supportsurface being free from welds, or (ii) formed by two separate sheetswelded to each other over the entire periphery thereof using at leastfour welds: a lower longitudinal weld, two side welds, and an upperlongitudinal weld, said cell including one or more additional welds thatare spaced apart along the length of the housing, and that make itpossible to connect the two main opposed side surfaces of the housing toeach other, the distance (e₁) between each additional end weld and theadjacent side weld of the housing, measured along the longitudinal axisof the housing, being greater than or equal to the distance (e₂) betweensaid additional end weld and (i) the upper bend line of the sheetforming the housing, or (ii) the upper longitudinal weld, such that whenthe housing is inflated, the support surface is deformed so as to have abasin-shaped fall prevention curve profile with raised ends.
 37. Thecell according to claim 36, wherein the upper support surface of thedeflated housing has a substantially rectilinear profile over the entirelength of the housing.
 38. The cell according to claim 36, wherein theadditional weld(s) are oblong.
 39. The cell according to claim 38,wherein the oblong additional weld(s) are oriented so that their mainlongitudinal axis is substantially parallel to the main longitudinalaxis of the housing, and define at least two superimposed inflationchambers that communicate with each other.
 40. The cell according toclaim 38 wherein the main longitudinal axis of the oblong additionalwelds is substantially perpendicular to the main longitudinal axis ofthe housing.
 41. The cell according to claim 40, wherein the length (L₃)of each additional oblong weld is at least equal to 30% of the maximumheight (H₁) of the deflated housing.
 42. The cell according to claim 36,comprising an inner sheet positioned between the two main side surfacesof the housing, which is welded to said main side surfaces via saidadditional welds, and which makes it possible to limit the expansion ofthe cell.
 43. The cell according to claim 40, wherein the length (L₃) ofeach additional oblong weld is at least equal to 50% of the height (H₄)of the inner sheet.
 44. The cell according to claim 36, wherein the twomain opposed side surfaces are welded together directly via saidadditional welds.
 45. The cell according to claim 36, wherein theadditional welds are substantially centered on the height of the housingof the cell.
 46. The cell according to claim 36, wherein said lowerlongitudinal weld having a curve profile that is made so that when thehousing is inflated, the support surface is deformed so as to have abasin-shaped fall prevention profile with raised ends.
 47. The cellaccording to claim 46, wherein said lower longitudinal weld has a bowedcurve profile whereof the apex is oriented towards the support surface,such that when the housing is inflated, the support surface is deformedso as to have a basin-shaped fall prevention curve profile with raisedends.
 48. The cell according to claim 47, wherein when the housing isdeflated, the height H₁ between the apex of said lower longitudinal weldis smaller than the height H₂ at the ends of the housing.
 49. The cellaccording to claim 46, wherein said lower longitudinal weld has a curveprofile such that the height at the center H₁ of the deflated housing issmaller than the height H₂ at the ends of the deflated housing.
 50. Thecell according to claim 48, wherein the height difference ΔH (ΔH=H₁−H₂)between the heights H₁ and H₂ is at least equal to 3 cm, and preferablyat least equal to 5 cm.
 51. An inflatable cell for anti-escharmattresses, said cell includes an inflatable housing having an elongateshape and two main opposed side surfaces, an upper surface that forms anupper support surface when the housing is inflated, and one or severaloblong welds, the main longitudinal axis of which is substantiallyparallel to the main longitudinal axis of the housing, and which make itpossible to connect the two main opposed side surfaces of the housing toeach other, so as to define, in the housing, at least two superimposedinflation chambers that communicate with each other, wherein the uppersupport surface of the deflated housing has a substantially rectilinearprofile over the entire length of the housing, and the oblong weld(s)are made so that when the housing is inflated, the support surface isdeformed so as to have a basin-shaped curved fall prevention profilewith raised ends.
 52. The cell according to claim 51, wherein the weldsin a line are identical, and in that the spacing (d) between the weldsof a line is substantially constant.
 53. The cell according to claim 51,wherein the two main side surfaces are welded together via a singleoblong weld whereof the main longitudinal axis is substantially parallelto the main longitudinal axis of the cell.
 54. The cell according toclaim 51, wherein the superimposed inflation chambers have substantiallythe same volume.
 55. The cell according to claim 51, wherein the totallength of the welds of a line or the sole oblong weld is at least equalto 40% of the total length (L₂) of the inflation chambers.
 56. The cellaccording to claim 51, wherein the maximum width (L_(max)) of the uppersupport surface of the inflated cell is between 6 cm and 9 cm.
 57. Thecell according to claim 51, wherein the maximum width (L_(max)) of theupper support surface of the inflated cell is smaller than the height(H′) of the inflated cell.
 58. The cell according to claim 51,comprising an inflation stem for inflating/deflating the superimposedchambers of the housing.
 59. The cell according to claim 51, wherein thehousing is formed by a sheet folded in two lengthwise, and welded onthree sides of the periphery thereof using a lower longitudinal weld andtwo side welds, the support surface being free of welds.
 60. The cellaccording to claim 59, wherein the distance (e₁) between each end weldand the adjacent side weld of the housing, measured along thelongitudinal axis of the housing is greater than or equal to thedistance (e₂) between said end weld and the upper bend line of the sheetforming the housing.
 61. The cell according to claim 51, wherein saidhousing is formed by two separate sheets welded together over the entireperiphery thereof via at least four welds: a lower longitudinal weld,two side welds, and an upper longitudinal weld.
 62. The cell accordingto claim 61, wherein the distance (e₁) between each end weld and theadjacent side weld of the housing, measured along the longitudinal axisof the housing, is greater than or equal to the distance (e₂) betweensaid end weld and the upper weld.
 63. The cell according to claim 51,wherein said inflated housing comprises two end surfaces, and thedistance (e1) separating each end surface from the closest longitudinalweld and which is measured along the longitudinal axis of the housing,is greater than or equal to the distance (e₂) separating saidlongitudinal weld and the support surface.
 64. The cell according toclaim 59, wherein said lower longitudinal weld having a curve profilemade so that when the housing is inflated, the support surface isdeformed so as to have a basin-shaped fall prevention curve profile withraised ends.
 65. The cell according to claim 64, wherein said lowerlongitudinal weld has a bowed curve profile whereof the apex is orientedtowards the support surface, so that when the housing is inflated, thesupport surface is deformed so as to have a basin-shaped fall preventioncurve profile with raised ends.
 66. The cell according to claim 64,wherein when the housing is deflated, the height H₁, between the apex ofsaid lower longitudinal weld is smaller than the height H₂ at the endsof the housing.
 67. The cell according to claim 64, wherein said lowerlongitudinal weld has a curve profile such that the height at the centerH₁ of the deflated housing is smaller than the height H₂ at the ends ofthe deflated housing.
 68. The cell according to claim 66, wherein theheight difference ΔH (ΔH=H₁−H₂) between the heights H₁ and H₂ is atleast equal to 3 cm, and preferably at least equal to 5 cm.
 69. Ananti-eschar mattress, comprising a plurality of the inflatable cellsaccording to claim 1, which are positioned transversely to thelongitudinal axis of the mattress, and which are juxtaposed along saidlongitudinal axis.
 70. An anti-eschar mattress, comprising a pluralityof the inflatable cells according to claim 36, which are positionedtransversely to the longitudinal axis of the mattress, and which arejuxtaposed along said longitudinal axis.
 71. An anti-eschar mattress,comprising a plurality of the inflatable cells according to claim 51,which are positioned transversely to the longitudinal axis of themattress, and which are juxtaposed along said longitudinal axis.